Liquid tank trucks are widely used in a variety of situations to transport liquids. Gasoline delivery trucks, oil field vacuum trucks, septic tank service trucks, oil hauling trucks and the like comprise a large generally cylindrical tank into which the liquid is delivered and then emptied. Typically, these type trucks have a conduit stub extending horizontally from the tank. A hose assembly connects to the conduit stub and delivers the liquid to or from the tank. The hose assembly includes a central flexible hose having a male coupling on one end and a female coupling on the other end. The female coupling includes a rigid coupling end having a female connection receiving the conduit stub and a locking mechanism to secure the conduit stub in place. The locking mechanisms have evolved over the years but are now substantially standardized and include a pair of levers pivoted to the exterior of the rigid coupling end and a cam extending into the interior of the female coupling for engaging and latching into a circular recess on the conduit stub. Operation of the levers causes the cams to engage the recess and force the coupling halves toward each other. A seal in the female coupling engages the end face of the conduit stub and prevents leaking during liquid exchange.
The male connection on the hose assembly is normally substantially identical to the conduit stub so substantially identical hose assemblies may be attached, end to end, to provide a longer assembly.
Pipe end protectors are known in the prior art as shown in U.S. Pat. Nos. 1,810,948; 1,934,681; 3,352,574; 3,744,528; 3,818,946; 4,269,232; 4,799,716; and 5,383,494. Plastic or metal pipe end protectors are also well known in the oil field where the protector is threaded on each end of a pipe joint to protect the threads during transportation. Protection of threads on the male end is much more important because they are exposed. Pipe end protectors of this type are universally removed before the pipe is used in its normal and intended fashion.